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Dynamic Light Scattering

DLS is a non invasive technique and it is well established for measuring the size of molecules and particles in the submicron region.

This method offers several advantages:

  • Measures particle sizes of 1 nm to 1/10 of the wavelength of the light
  • Typically ±1% precision
  • Short experiment duration (1-2 min)
  • Reliable and repeatable analysis
  • Straightforward sample preparation
  • Low sample volumes (as low as 2 uL)
  • Modest development costs

ID100 Single Photon Counter

The ID100 single photon counters are based on a reliable silicon avalanche photodiode (APD) sensitive in the visible spectrum. The modules are able to detect weak optical signals down to the single photon level. With their very low dark count rates, timing resolution of 40 ps and dead time of 45 ns, the modules have an unmatched dynamic range.

The ID100 is easy-to-use, self-contained and can easily be integrated in every optical set-up. Besides a very narrow Instrument Response Function (IRF) it has an excellent timing stability up to count rates of at least 10 MHz. The ID100 is available in the following versions:

  • ID100-20: free space coupling with 20 mm active area
  • ID100-50: free space coupling with 50 mm active area
  • ID100-SMF20: Single Mode Fiber coupling with 20 mm active area
  • ID100-MMF50: with 50/125 μm FC/PC Multi Mode Fiber coupling
  • ID100-MMF50: with 100/140 μm FC/PC Multi Mode Fiber coupling

The ID100 modules exist in two grades, depending on the dark count rate specifications. For the Ultra-Low Noise grade, the dark count rate is less than 5 Hz for the ID100-20 and less than 20 Hz for the ID100-50 and ID100-MMF50. The key features are:

  • Broad spectral range: 350 to 900 nm
  • Best in class timing resolution of 40 ps
  • Low dark count rate of less than 5 Hz
  • Low dead time (45 ns)
  • Photon detection probability up to 35%
  • Standard 50 Ω output with BNC connector
  • Fast active quenching circuit
  • Low bias voltage +5 V
  • Not damaged by strong illumination

For the measurements mentioned below, the ID100-MMF50 detector was used to compute the scattered light intensity.


Application Notes